Analyzing S-Parameter Variations in Metamaterials: The Impact of Varying Incident Angles for Electromagnetic Waves

The study investigates how changing the incident angle (
$\theta$
) of electromagnetic waves impacts the structure's frequency response. When
$\theta$
exceeds 45 degrees, the structure exhibits a heightened sensitivity to the 2nd harmonic, diminishing the 1st harmonic's amplitude. Notably, the 2nd harmonic disappears entirely at
$\theta= 90$
degrees. Within the 0 to 45-degree range, the response aligns with the 1st harmonic. However, the center frequency remains sensitive to
$\theta$
, increasing as
$\theta$
rises. Figures 7 to 12 illustrate these effects, revealing that altering the incident angle of
$\theta$
waves not only shifts the center frequency but also induces changes in the metamaterial properties, impacting its characteristics.